TSIG (or nsupdate) key generation, take two (improved)

tsig-gen-v2.sh

#!/usr/bin/env bash
# quick and dirty TSIG generation script
# version 2
# mostly taken directly from https://github.com/Neilpang/acme.sh/tree/master/dnsapi
# (with a sprinkle of added command-line switching)

# define key params
size="512"
algo="hmac-sha$size"

# get key name
if [[ -z $1 ]]; then
    echo "Error: Usage: $0 <key-name>"
    exit 1
else
    keyname="$1"
fi

tsig=$(dnssec-keygen -a $algo -b $size -n USER -K /tmp $keyname)
cat <<EOF
key "$keyname" {
    algorithm $algo;
    secret "$(awk '/^Key/{print $2}' /tmp/$tsig.private)";
};
EOF
rm -f /tmp/$tsig.{private,key}